isContextLost method
The CanvasRenderingContext2D.isContextLost() method of the Canvas 2D
API returns true if the rendering context is lost (and has not yet been
reset).
This might occur due to driver crashes, running out of memory, and so on.
If the user agent detects that the canvas backing storage is lost it will
fire the
contextlost event
at the associated
HTMLCanvasElement.
If this event is not cancelled it will attempt to reset the backing
storage to the default state (this is equivalent to calling
CanvasRenderingContext2D.reset).
On success it will fire the
contextrestored event,
indicating that the context is ready to reinitialize and redraw.
Implementation
external bool isContextLost();